Fiber optics has become the core of telecommunications and data networking infrastructures. To use optical fibers effectively for communications, demountable connections are required. A connector allows a demountable connection between fibers or between a fiber and a source or detector.
The most common design for fiber optic connectors uses precision ferrules to hold the optical fiber. The ferrule (terminus) on one side of a connection is held in a bushing/adapter (female side), which is secured inside an assembly or on a bulkhead. The other side (male) is pushed into the bushing/adapter to make the optical connection. In order for the connector to have low loss, the surfaces of the ferrules must be perfectly clean and free of obstructions that might otherwise block the light transmission. Cleanliness of fiber optic connectors is recognized as a basic requirement for the successful operation of optical networks.
A ferrule is a cylindrical part made of zirconia ceramics measuring 1.25 mm (MU type) or 1.6 mm (MIL-T-29504 terminus) or 2.5 mm (SC type) in diameter. Ferrules are manufactured with ultra-precision, and hold an optic fiber with a diameter of 0.125 mm or less.
Fiber optic connectors need to be cleaned every time they are mated and unmated. They also need to be mated or covered immediately after cleaning. Dust particles smaller than 1 μm can be suspended almost indefinitely in the air. A 1 μm dust particle landing on the core of a single-mode fiber, which can have a core size as small as 8–9 μm, can cause up to 1 dB of loss. 9 μm or larger dust particles can completely obscure the core of a single-mode fiber. As a point of reference, a typical human hair is about 50–75 μm in diameter.
The current approach for cleaning the optical fiber connector contains two parts: one for plug ferrule (male) and another for connector adapter (female). Commercially available cleaning tools are reasonably effective for cleaning the male form of a fiber-optic connector. The known CLETOP® optical fiber cleaner contains a spooled, woven-film cleaning cloth that is concealed by a shutter. The reel-type CELTOP cleaner is reasonably effective in cleaning the plug ferrules (male) of fiber connectors The stick-type CELTOP cleaner applies the same dry cloth as used in the reel-type. The stick-type CELTOP cleaner is used to clean connector ferrules in difficult to reach spots such as the inside of adapters.
Some existing fiber optic connecter cleaners have air and solvent delivery and removal systems. However, these prior cleaning systems are cumbersome and each usually weighs at least 10 pounds. They typically use mechanical pumps to produce compressed air to deliver solvent, vacuum pumps to produce vacuum to remove the waste solvent, and solenoid valves to control the process of the cleaning. These traditional pumps and valves are big and weigh more than a few pounds. They also need high electric power—a few hundred watts—to operate.
In view of the foregoing, there is a continuing need in the art for an efficient and effective fiber optic connector cleaner that can be made economically and that is lightweight, self-contained, and small in size. Such a fiber optic connector cleaner should be able to remove both particles and contaminants without scratching the fiber optic connector surfaces and without requiring that the connector be disassembled. It should be able to effectively and efficiently clean all types of fiber optic connectors, including male and female, and able to handle military MIL-T-29504 termini as well as standard fiber optic connectors in 1.25- and 2.5-mm diameters. The present invention addresses this need.